Safety knife



FIG. 1 is a perspective view of a safety knife showing a first blade position;

FIG. 2 is a reverse perspective view of the safety knife of FIG. 1.

FIG. 3 is a front view of the safety knife of FIG. 1;

FIG. 4 is a back view of the safety knife of FIG. 1;

FIG. 5 is a front view of a safety knife showing a second blade position;

FIG. 6 is a back view of the safety knife of FIG. 5; and,

FIG. 7 is a reverse perspective view of the safety knife of FIG. 5. 

CLAIM The ornamental design for a safety knife, as shown. 